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App

App​

The App struct is the main application container that orchestrates the entire chess-tui application.

Responsibilities​

The App struct manages:

  • Application lifecycle and state - running flag, pages, popups
  • Game configuration - chess engine path, bot depth, display mode
  • Bot move computation - background threads for async bot thinking
  • Multiplayer server setup - opponent connections and game server
  • Menu navigation - user input handling and page transitions
  • Configuration file management - ~/.config/chess-tui/config.toml

Key Fields​

pub struct App {
    pub running: bool,                          // Application running state
    pub game: Game,                             // The chess game instance
    pub current_page: Pages,                   // Current page (Home, Solo, Multiplayer, Bot, Credit)
    pub current_popup: Option<Popups>,         // Active popup (Help, ColorSelection, etc.)
    pub selected_color: Option<Color>,          // Selected color when playing against bot
    pub hosting: Option<bool>,                  // Whether hosting a multiplayer game
    pub host_ip: Option<String>,                // Host IP address for multiplayer
    pub menu_cursor: u8,                       // Menu navigation cursor
    pub chess_engine_path: Option<String>,     // Path to UCI chess engine
    pub log_level: LevelFilter,                 // Logging level
    pub bot_depth: u8,                          // Bot thinking depth (1-255)
    pub bot_move_receiver: Option<Receiver<Move>>, // Channel receiver for bot moves
    pub error_message: Option<String>,          // Error message for Error popup
}

Key Methods​

Bot Management​

  • start_bot_thinking() - Spawns a background thread to compute bot moves asynchronously
  • check_bot_move() - Checks if bot move is ready and applies it to the game
  • is_bot_thinking() - Returns whether bot is currently computing a move
  • apply_bot_move(Move) - Applies a computed bot move to the game board

Game Setup​

  • bot_setup() - Initializes bot with engine path and depth
  • create_opponent() - Sets up multiplayer opponent connection
  • setup_game_server(host_color: Color) - Starts game server for hosting
  • hosting_selection() - Handles host/client selection in multiplayer
  • go_to_home() - Returns to home page and restarts game
  • menu_select() - Handles menu item selection
  • menu_cursor_up/down/left/right(l: u8) - Navigates menu cursor

Configuration​

  • update_config() - Writes current settings to config file
  • get_host_ip() - Retrieves local IP address for multiplayer hosting

Game Control​

  • restart() - Resets game while preserving bot/opponent setup
  • reset() - Complete reset of all game state
  • quit() - Exits the application

Bot Async Architecture​

Bot moves are computed asynchronously to keep the UI responsive:

  1. start_bot_thinking() spawns a thread that:

    • Creates a new Bot instance in the thread
    • Gets the current FEN position
    • Computes the best move using the UCI engine
    • Sends the move through a channel (bot_move_receiver)

  2. check_bot_move() is called each frame to:

    • Check if a move is ready in the channel
    • Apply the move if available
    • Clear the receiver

  3. is_bot_thinking() prevents starting multiple bot threads simultaneously

This architecture ensures the UI remains responsive even when the chess engine takes time to compute moves.